Investigation Sheds New Light on Legacy Toxins

On March 18th, the District Department of Energy and Environment (DOEE) released the first phase of a report investigating the levels of toxic chemicals trapped in the sediment along the tidal portion of the Anacostia River.
The international engineering consulting firm TetraTech developed the “remedial investigation” report on contract to the DOEE. TetraTech’s remedial investigation began in the summer of 2014. Its written report is 174 pages long, not including maps, tables, and figures included on two DVD disks. DOEE is managing the entire investigation and cleanup process in accordance with a federal law known as the Comprehensive Environmental Response, Compensation, and Liability Act.

The remedial investigation report is highly technical and difficult for the layperson to follow. In general, it confirms that legacy toxins from former industrial, military, commercial or municipal activities along the Anacostia waterfront and further up in the watershed continue to poison the river. The primary concerns are polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), although pesticides, lead and other trace elements were also found. PCBs and PAHs are implicated in a number of adverse health effects for human beings and animals.

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As any paddler who has taken a kayak or canoe onto the Anacostia can attest, it is a gentle river. A very gradual slope causes fresh water from the upper watershed to move slowly towards the Potomac. Slightly saline water from the Chesapeake Bay and the lower Potomac comes in on the tides as far upstream as Bladensburg, MD. The result of these two forces is that sediments and chemicals in the water tend to settle out quickly. Toxics from past industrial uses are often found deep in the sediments, but are stirred up into the water column when storms add volume and speed to the river.

PCBs, the manufacture of which was banned in 1976, have been shown to lead to developmental defects, numerous cancers, and several other problems. PAHs are believed to cause skin lesions and cancerous tumors in fish and other aquatic creatures.

Absorbed by plants or consumed by invertebrates in the bottom sediments, which are then consumed by fish, PCBs and PAHs move up the food chain, concentrating as they go. Although the District warns people not to consume catfish, carp, or American eels from the Anacostia, studies have shown that up to 17,000 people a year consume fish pulled from these polluted waters.

The human health risk assessment associated with the report suggests that populations most at risk are swimmers and waders, and recreational fishers. As is too often the case, the poorest among us are the most vulnerable, particularly subsistence fishers since they frequently consume fish from river, despite the warnings and health risks.

The next stage of the process is developing cleanup feasibility studies, which may involve dredging, “capping” or other techniques. DC law requires the Department of Energy and Environment to select a cleanup option and issue a public “Record of Decision” by June 2018. Further plans for the cleanup will be based on the chosen option, and parties responsible for the pollution are required to pay for it.